The present invention relates to a satellite radio-wave reception device that receives a radio wave from a positioning satellite, a radio controlled watch, an information acquisition method, and a recording medium.
Conventionally, there is an electronic clock (radio controlled watch) having a function of keeping a counted date and time accurate by receiving a radio wave from a navigation satellite (positioning satellite) according to a global navigation satellite system (GNSS) and by acquiring date-and-time information. In this radio controlled watch, it is possible to keep a counted and displayed date and time accurate in each place in the world without manual operation of a user.
However, a load related to reception of a satellite radio wave is significantly high compared to a load related to counting or displaying of a date and time in an electronic clock. Thus, in a response to reception of a satellite radio wave, there is a problem that a size of a battery is increased and that a size and weight of an electronic clock is increased accordingly. Thus, conventionally, various technologies to reduce a power consumption related to reception of a satellite radio wave have been developed.
As such a technology of reducing power consumption, there is reduction of radio wave reception time. For example, in Japanese Patent Application Laid-Open No. 2009-36748, a technology of performing reception at transmission timing of a predetermined part including date-and-time information according to a format of a signal transmitted from a GPS satellite (navigation message) and of temporarily stopping the reception while unnecessary information is transmitted is disclosed. Here, in order to avoid erroneous identification of a date and time, parity data corresponding to a block including the predetermined part is calculated and consistency of reception data is checked.
However, when necessary time information is decrypted after identification of each received code and a collation operation such as a parity check is further performed, there is a problem that a load of processing in radio wave reception is eventually increased and that memory capacity or power consumption is increased.